This invention relates to an engine cooling system and more particularly to an improved coolant pump and coolant circulation system for a liquid cooled internal combustion engine.
As is well known, liquid cooled internal combustion engines have cooling jackets formed in their cylinder block and/or cylinder head through which liquid coolant, normally water or a mixture of water and antifreeze, are circulated. Generally, the coolant pump is mounted on an external face of the engine and is driven from the engine crankshaft for circulating the liquid coolant. In addition to the coolant pump, a number of other accessories for the engine are driven by the crankshaft, and these may include one or more camshafts, an alternator or generator, power steering pumps, air conditioning compressors, vacuum pumps, and a wide variety of other components. These accessories are driven by one or more flexible transmitters, which may include both chains and/or belts. Normally, the coolant pump is mounted on the end of the engine where the other accessories are driven, and this gives rise to certain difficulties.
For example, it is desirable to place the water pump so that it can be mounted directly on one of the major engine castings so as to minimize the number of external coolant conduits. However, the coolant pump should also be mounted in such a location that it can be easily serviced. This means that the coolant pump is generally positioned on the outside of the timing case that contains the driving mechanism for the camshafts for the engine. This obviously makes it difficult to mount the water pump in direct relationship to the cooling passages of the cylinder block or cylinder head.
Also, it is desirable to mount the various components that are driven in such a way that all or many of them can be driven by a single flexible transmitter. This necessitates positioning of the pulleys on the drive shafts for the various accessories in the same plane. This is very difficult with the type of engine constructions previously employed.
Frequently, in addition to the engine being liquid cooled, there is provided a heat exchanger for cooling the lubricating oil. It is desirable if this heat exchanger can be cooled by the same coolant that is circulated through the engine. This adds to the number of external conduits which must be employed with the previous types of construction, and gives rise to the possibility of leaks and further complicates the driving arrangement for the system.
It is, therefore, a principal object of this invention to provide an improved arrangement for mounting and driving the coolant pump of a liquid cooled internal combustion engine.
It is a further object of this invention to provide an improved and compact liquid coolant pump for an internal combustion engine that minimizes the number of external components and which permits all accessories to be driven by a single flexible transmitter.